JP4606298B2 - Image processing apparatus, image processing method, and image processing program - Google Patents

Description

  The present invention relates to an image processing device, an image processing method, and an image processing program, and more particularly to an image processing device, an image processing method, and an image processing program capable of processing image information including a region where browsing is restricted.

  In general, encryption processing, scramble processing, and the like have been performed in order to distribute digital data such as images, documents, and videos in a secret manner so that only the authorized person can understand. This is because the entire data is encrypted in advance using one encryption key, and only the authorized person owns the decryption key corresponding to this encryption key, so only the authorized person can decrypt and view the contents. Is possible.

For example, Patent Document 1 below discloses a method of dividing a document image into a text layer and an image layer and encrypting or scrambling a specific area of a layer to be concealed, thereby finely managing access rights. be able to.
JP 2004-289456 A

  However, in the method disclosed in Patent Document 1, a file to be created has a special configuration including management information such as access rights, and even a person who does not have the right to view a secret layer can manage the file. In order to display the non-hidden layer, a special device or software capable of interpreting this file structure must be prepared. This causes a problem that access right management is complicated in the image display apparatus.

  In addition, even if you are a person who does not have the authority to view image information that is restricted and concealed, you can use a general-purpose image display device or software that does not require special devices or software. It may be desirable to be able to see part of the content.

  The present invention has been made in view of such a problem, and at least a part of browsing is restricted, and an image that can be appropriately processed with respect to image information that is concealed from unauthorized users. An object is to provide a processing device, an image processing method, and an image processing program.

In order to achieve the above object, according to one aspect of the present invention, an image processing apparatus includes an image reading unit that reads an input image, an image obtained by extracting an area to be encrypted from the input image, and other areas that are not encrypted. A layer image generating means for generating a plurality of layer images obtained by separating each of the images, and a region to be encrypted from the input image as a layer image to be encrypted from the plurality of layer images. and layer selection means for selecting a layer image obtained, the encryption key generating means for generating an encryption key for encrypting the layer image is selected, the layer image selected by the layer selection means using the encryption key Encryption processing means for encryption, layer images generated by the layer image generation means, the layer image encrypted by the encryption processing means, and the encryption processing means Therefore comprising an image encoding means for each encoding the layer image unencrypted, and data storage means for storing encoded data comprising a plurality of layer images coded by the image coding unit.
Preferably, the layer image generation means includes a first layer image obtained by extracting a region in which text is written in the input image, and a second layer image obtained by extracting an image other than text in the input image. A plurality of layer images are generated.

Specifically, the layer image generation means extracts a first layer image obtained by extracting a first region including text in the input image and a second region obtained by extracting a second region other than the first region in the input image. Generating a layer image and a third layer image indicating which of the first layer image and the second layer image to be displayed at each point when decoding is performed; selecting means preferably selects one of the first layer image and the second layer image.

Alternatively, the layer image generation means includes a first layer image obtained by extracting a first region to be encrypted in the input image and a second layer obtained by extracting a second region other than the first region in the input image. Generating an image and a third layer image indicating which one of the first layer image and the second layer image to display at each point when decoding the encoding, and selecting the layer The means preferably selects the first layer image.
Preferably, the layer image generation unit generates a plurality of layer images from the input image for each encryption key, and the encryption processing unit generates a plurality of layer images generated by the layer image generation unit according to the encryption key for each encryption key. The selected layer image of the layer images is encrypted.
Preferably, the image encoding means encodes each generated layer image.

  Alternatively, the layer image generation means extracts the first layer image obtained by extracting the first region to be encrypted from the input image, and the second region other than the first region from the input image, and further extracts the first region. It is preferable that a second layer image including a region representing transparency corresponding to one region is generated, and the layer selecting unit selects the first layer image.

  Preferably, the image reading unit reads encoded data as an input image, and the layer image generating unit generates a plurality of layer images from layer images included in the input image that is encoded data.

  Specifically, it is preferable that the encryption processing means encrypts the layer image using a common key encryption method or a public key encryption method.

  Further, it is preferable that the encryption key generation unit generates the encryption key based on a unique identifier of a user who has the authority to decrypt the encrypted layer image.

According to another aspect of the present invention, the image processing apparatus includes an image reading unit that reads the encoded data generated by the above-described image processing apparatus as an input image, and a layer image that extracts a layer image encoded from the input image. A reading unit; an image decoding unit that decodes the encoded layer image; an encrypted layer image obtaining unit that extracts an encrypted layer image from the decoded layer image; and an encrypted layer image An encryption key obtaining unit for obtaining an encryption key for decryption, an encryption layer decrypting unit for decrypting a layer image encrypted using the encryption key, and a layer image decrypted by the image decrypting unit, Output data generating means for generating output data from the layer image decrypted by the encryption layer decrypting means and the unencrypted layer image.

According to still another aspect of the present invention, an image processing method includes a step of reading an input image in an image reading unit of an image processing device, an image obtained by extracting an area to be encrypted from the input image, and other areas not to be encrypted. comprising the steps of by separating the image generating a plurality of layer images obtained respectively, from the input image as the layer image to be encrypted from a plurality of layer images obtained by separating the area to be encrypted A layer image selection step, a step of encrypting the selected layer image, and a plurality of generated layer images, each of an encrypted layer image and an unencrypted layer image. A step of encoding, and a step of outputting encoded data including a plurality of encoded layer images from the image processing apparatus.

According to still another aspect of the present invention, an image processing method includes a step of reading encoded data generated by the above-described image processing method as an input image in an image reading unit of an image processing device, and an encoding from the input image. A step of extracting the layer image, a step of decoding the encoded layer image, a step of extracting the encrypted layer image from the decoded layer image, and a step of decoding the encrypted layer image And a step of generating output data from a layer image that has been encoded and decoded, and a layer image that has not been encrypted.

According to still another aspect of the present invention, an image processing program is a program for causing a computer to execute image processing in an image processing device, and reading an input image in an image reading unit of the image processing device; and generating a plurality of layer images respectively obtained by separating the image of the region without images and other cryptographic extracting the area to be encrypted, as the layer image to be encrypted from a plurality of layer images A step of selecting a layer image obtained by separating a region to be encrypted from an input image; a step of encrypting the selected layer image; and a plurality of generated layer images, wherein the layer image is encrypted. The encoded layer image and the unencrypted layer image, respectively, and the image processing device And a step of outputting the coded data including a plurality of layer images.

According to still another aspect of the present invention, the image processing program is a program for causing a computer to execute image processing in the image processing apparatus, and is generated by the computer by the above-described image processing program in the image reading unit of the image processing apparatus . A step of reading encoded data as an input image , a step of extracting a layer image encoded from the input image, a step of decoding the encoded layer image, and the encrypted layer image are encrypted. A step of extracting the layer image, a step of decrypting the encrypted layer image, a layer image obtained by decoding, a layer image obtained by decrypting encryption, and a layer image not encrypted Generating output data from the output.

  According to still another aspect of the present invention, the recording medium is a computer-readable recording medium and records the image processing program.

  An image processing apparatus according to an aspect of the present invention can be configured by a general-purpose image processing apparatus, which decodes a plurality of encoded layer images included in image data and generates output data. At that time, even if the image processing apparatus does not have means for decrypting the encrypted data, or even if the encryption key is not acquired, the encrypted layer image is encrypted. The encoding is decoded as it is, and output data is generated.

  Therefore, in a general-purpose image processing apparatus, even if there is no encryption key, an image other than the encrypted secret part can be viewed, so even a user who restricts browsing of the secret part knows the outline. be able to.

  In addition, the image processing apparatus according to another aspect of the present invention employs an encoding method such as MRC, for example, to divide the target image into a plurality of layers and encode each layer image using a different method. It is possible to conceal (scramble) characters and images.

  Further, by making each of the plurality of areas into layers, it is possible to easily set the access right to the image data without using special means such as management information to manage it.

  Further, image processing for restricting browsing of a part of an image can be executed even by a user who is restricted from browsing the image.

  Embodiments of the present invention will be described below with reference to the drawings. In the following description, the same parts and components are denoted by the same reference numerals. Their names and functions are also the same.

  FIG. 1 is a block diagram illustrating a specific example of the apparatus configuration of the image processing apparatus 100 according to the present embodiment. The image processing apparatus 100 according to the present embodiment is realized by an apparatus such as a general-purpose personal computer, and the apparatus configuration shown in FIG. 1 is an apparatus configuration such as a general personal computer.

  Referring to FIG. 1, an image processing apparatus 100 according to the present embodiment includes a CPU (Central Processing Unit) 500 that controls the whole.

  The CPU 500 is connected to the bus 510 with a display 501, a keyboard 502, a scanner 503, a printer 504, a main memory 505, an external memory 506, a mouse 507, a speaker 508, and a communication device 509, and performs each part while exchanging data. Control and perform image processing. A program for realizing image processing in the image processing apparatus 100 is acquired from a main storage 505, an external storage 506, a network destination via the communication device 509, and the like.

  Data exchange may be performed not only via the bus 510 but also via a communication cable or a wireless communication device that can transmit and receive data.

  The display 501 is usually realized in combination with a graphic chip, a video random access memory (VRAM), etc., converts data on the VRAM into a display signal, and sends it to a display (display / output medium) such as a liquid crystal display. Displays the display signal as an image.

  As means for inputting user instructions, there are a keyboard 502, a mouse 507, and the like. The user instructions are input to each unit via the bus 510. In addition, various input devices such as various operation devices and voice input using a microphone can be used. The keyboard 502 includes a mechanical or electronic switch that detects a pressed key. The mouse 507 includes a mechanical or electronic switch that detects a pressed state of a mouse button, and a mechanical or electronic sensor that detects a relative movement distance in the vertical and horizontal directions of the mouse.

  The main memory 505 is usually composed of a memory device such as a DRAM (Dynamic Random Access Memory) or a flash memory. Note that a memory or a register included in the CPU 500 may be interpreted as a kind of main memory.

  The external recording device 506 is a device that records data on a removable storage medium 511 such as an HDD (Hard Disk Drive) or a PC (Personal Computer) card. Alternatively, the CPU 500 and the communication device 509 can also be used as the external storage medium 511, which is a main memory 505 or an external memory 506 attached to another network device that is wired or wirelessly connected via a network.

  The scanner 503 is a device that reads a printed matter such as a photograph or a document and converts it into a digital image. The read digital image is stored in the main memory 506 or the external memory 506 via the bus 510 or processed by the CPU 500.

  The printer 504 is a device that prints image data such as digitized documents and photographs sent via the bus 510 on a print medium such as paper.

  The communication device 509 is realized by a network interface card (NIC) or the like, and exchanges data with other network devices connected by wireless or wired.

  The speaker 508 interprets audio data sent via the bus 510 or the like as an audio signal and outputs it as audio. The output sound may be a simple single wavelength sound or may be complicated such as music or human voice. If the sound to be output is determined in advance, the transmitted data may not be a sound signal but simply an on / off operation control signal.

  FIG. 2 is a block diagram illustrating a specific example of a functional configuration for performing image processing according to the present embodiment in the image processing apparatus 100. Each function illustrated in FIG. 2 is a function formed in the CPU 500 by executing a program acquired by the CPU 500 from the main memory 505 or the like.

  Referring to FIG. 2, the image processing apparatus 100 includes an image reading unit 101 that reads a previously created image, a layer image generation unit 102 that generates a plurality of layer images from the read image, and a plurality of layer images. The layer selection unit 103 that selects a layer image to be encrypted from, the encryption key generation unit 104 that generates an encryption key for performing an encryption process, and the encryption key that generated the selected layer image is used for encryption The encryption processing unit 105 includes an image encoding unit 106 that encodes each layer image, and a data storage unit 107 that stores the encoded data, and includes an external recording device 506 and the like. .

  The image reading unit 101 is connected to the scanner 503, the main memory 506, and the like, reads image data, and inputs the read image to the layer image generation unit 102.

  The layer image generation unit 102 generates a plurality of layer images from the image input from the image reading unit 101. At this time, the layer image generation unit 102 is connected to a means for inputting user instructions such as the keyboard 502 and the mouse 507, the communication device 509, and the like, and restricts browsing of the read images as necessary. A plurality of layer images are generated based on a user instruction specifying a region to be performed (region including confidential information). Details of the plurality of layer images will be described later. The generated plurality of layer images are input to the layer selection unit 103.

  The layer selection unit 103 selects a layer image to be encrypted from a plurality of layer images input from the layer image generation unit 102. At this time, the layer selection unit 103 is connected to a means for inputting user instructions such as the keyboard 502 and the mouse 507, the communication device 509, and the like, and restricts browsing of the read image as necessary. A layer image to be encrypted is selected based on a user instruction that designates an area (an area including confidential information). The selected layer image is input to the encryption processing unit 105, and the unselected layer image is input to the image encoding unit 106.

  As an example, the encryption key generation unit 104 is connected to a means for inputting user instructions such as a keyboard 502 and a mouse 507, a communication device 509, and the like, and a user who permits browsing of an area of the image that restricts browsing. The unique identification information is acquired, and the encryption key is generated using the information. Specifically, the encryption key is generated by a method of using the identification information itself as an encryption key or a method of converting the identification information into an encryption key by a predetermined conversion process. In the present invention, the key generation method in the encryption key generation unit 104 is not limited to these methods.

  The encryption processing unit 105 acquires the encryption key from the encryption key generation unit 104, performs encryption processing on the layer image input from the layer selection unit 103, encrypts the layer image, and inputs the encrypted image to the image encoding unit 106.

  Here, “encryption processing” means conversion of normal unencrypted data (plaintext data) according to some rules, and conversion to data (encrypted data) that cannot be understood by a third party as it is In addition, there is a decryption process in which the ciphertext can be restored to the original plaintext by some rule (which may not be the same as the first rule). In encryption processing, different “keys” are generally used at the time of conversion so that the same plaintext is not always the same ciphertext.

  The types of encryption processing include a common key encryption method that can be decrypted by using the same “key” for the decryption processing, and a public key encryption method that can perform encryption processing and decryption processing with two keys of a predetermined pair. . Furthermore, common key cryptosystems include DES (Data Encryption Standard) and AES (Advanced Encryption Standard), and public key cryptosystems include RSA cryptography and Elgamal cryptography. The cryptographic processing unit 105 employs common key cryptography that performs processing in units of blocks among these methods, but other methods may be employed.

  The “encryption key” is arbitrary data that can be used for encryption processing, and is assigned one for each encryption processing. For example, in the case of a 64-bit key DES method, the “encryption key” is 64-bit data. However, the “encryption key” may be data such that a key used in the encryption process can be calculated by a predetermined conversion process.

  The image encoding unit 106 performs an encoding process on the unencrypted layer image input from the layer selection unit 103 and the encrypted layer image input from the encryption processing unit 105, respectively. And output to the data storage unit 107 as encoded data for storage. Alternatively, the encoded data may be output from the communication device 509 to the main storage 505 or the external storage 506 attached to another network device via the network and stored in those apparatuses.

The encoding process in the image encoding unit 106 will be described with a specific example.
As a method for efficiently encoding and compressing an image, there is an image encoding method called MRC (Mixed Raster Content). MRC is a technique in which, for example, an image is divided into three images of a fore layer, a mask layer, and a back layer, and each layer image is encoded by a different method. At this time, the fore layer and the back layer are color images, and the mask layer is a binary image. On the decoding side, based on the mask layer, it is selected which image of the fore layer or the back layer is displayed at each point.

FIG. 3 is a diagram for explaining an MRC that employs the first method as an example of the MRC.
Referring to FIG. 3, in the first method employed in MRC, forelayer 201, back layer 202, and mask layer 203 are extracted from the original image.

  The forelayer 201 is an image obtained by extracting an area in which text is written from the original image, and the back layer 202 is an image other than the above-described area, and is an image obtained by extracting an image such as a picture or a photograph. The mask layer 203 is a monochrome binary image, and is an image indicating which image of the fore layer and the back layer is displayed at each point at the time of decoding. More specifically, in the back layer 202, a black part indicates that the back layer 203 image is displayed during decoding, and a white part indicates that the fore layer 201 image is displayed during decoding. ing.

  In general, a text and an image such as a picture or a photograph often have different encoding methods because of different data structures. For this reason, the MRC employing the first method separates the text region and the image such as a picture or a photograph from the original image, and thus divides the original image into three layer images, which are suitable for each layer image. This is a technique capable of efficiently compressing a document image in which text and a photograph are mixed by an encoding method.

  When decoding an image encoded by the encoding method using the MRC employing the first method, a decoding method corresponding to the encoding method of each layer image is used, and the decoded forelayer 201 is used. The back layer 202 is output according to the mask layer 203. The output image 204 is displayed on a display or the like.

  Although three images are used in the first method, a second method different from the first method may be employed. FIG. 4 is a diagram illustrating an MRC that employs the second method as another example of the MRC.

  Referring to FIG. 4, in the second method adopted in MRC, the forelayer 201 and the backlayer 202 are extracted from the original image and replaced with the mask layer image 203 in the forelayer 201. A transparent color region 301 is newly provided.

  When decoding an image encoded by the encoding method using the MRC employing the second method, when the decoded forelayer 201 is overlapped with the back layer 202, only the transparent color region 301 is back layer. 202 images can be seen through. As a result, an image 204 similar to the example shown in FIG. 3 is output.

  Such a method for decoding data encoded using MRC is a method generally used in a general-purpose personal computer as shown in FIG. In many cases, a program for decoding data encoded by using is installed in advance.

  The image encoding unit 106 of the image processing apparatus 100 according to the present embodiment will be described as performing encoding using the MRC that employs the first method described above, but of course the MRC that employs the second method. Alternatively, encoding using another method having the same effect may be performed.

  FIG. 5 is a flowchart showing a flow of image processing in the image processing apparatus 100 according to the present embodiment. The process shown in the flowchart of FIG. 5 is realized by executing a program acquired by the CPU 500 from the main memory 505 and controlling each unit of FIG.

  Referring to FIG. 5, first, the image reading unit 101 reads the created image (S701).

  Next, in the layer image generation unit 102, an area to be encrypted in this image based on an instruction from the mouse 507, the keyboard 502, or the like, or an instruction received from another apparatus by the communication device 509 via the network If it is determined whether or not there is an area to be encrypted (YES in S702), a mask layer image for masking the area and an image obtained by extracting the area to be encrypted are included. A back layer image and a fore layer image including an image of another region (which does not require encryption) are created (S703). Alternatively, in place of the processing in steps S702 and S703, the layer image generation unit 102 analyzes the image read in step S701, and extracts a text-written region according to the analysis result. Then, a back layer image obtained by extracting an image such as a picture or a photo, and a mask layer image representing a combination of the fore layer image and the back layer image at the time of decoding may be created. Further, an encryption key is generated by the encryption key generation unit 104 (S704).

  The layer selection unit 103 selects a back layer image as an image to be encrypted from the images created in step S703, and the back layer encryption processing unit 105 uses the encryption key generated in step S704 to generate the back layer image. Encryption processing for encrypting only the image is executed (S705). Alternatively, in the layer selection unit 103, the layer image created in step S703 is based on an instruction from the mouse 507, the keyboard 502, or the like, or an instruction received from another apparatus by the communication device 509 via the network. Of these, at least one layer image to be encrypted may be selected.

  When the encryption process in step S705 ends, the process returns to step S702, and in the layer image generation unit 102, is there an area to be encrypted with another encryption key in the image read in step S701? If it is determined whether or not there is an area to be encrypted (YES in S702), the processes in and after step S703 are similarly repeated.

  On the other hand, if it is determined that there is no area to be encrypted with another encryption key (NO in S702), the image encoding unit 106 performs encoding for each layer image created by repeating steps S702 to S705. Processing is executed (S706). Then, the image encoding unit 106 combines the encoded layer images into one and stores them as encoded data in the data storage unit 107 (S707).

  In step S701, an image to be processed such as a scanned image is read, but the image read in step S701 is encoded data generated as a result of the image processing. The subsequent processing may be performed on the layer image extracted from the encoded data that is the input image. In step S701, the encoded data created as a result of the above-described image processing is read as an input image, and the subsequent processing is performed, so that an area to be encrypted is recursively added to the once created layer image. can do.

  FIG. 10 is a diagram for specifically explaining image processing when an area to be encrypted is added. In step S701, the encoded data generated as a result of the image processing, that is, the encoded data of the image (606) in which the layer 2 (603) having the confidential information is encrypted in the report 601 is read. In step S703, in the layer image generation unit 102, the unencrypted layer 1 (602) is changed to the layer (1101) not including the confidential information shown in FIG. 10 (D1) and the instruction 10 (D3). The image is divided into an image with a layer (1102) having an area to be encrypted as confidential information, which is determined based on an instruction or the like. Further, which layer is displayed in which region is specified by the mask layer (1103). That is, when decrypted, the layer (603) obtained by decrypting the first encrypted layer (605) that has already been encrypted is selected from the mask layer (1103), and the gray portion An image of a layer (1102) that has confidential information and is newly encrypted is selected, and a layer (1101) that does not include confidential information is selected as a white portion (non-masked portion).

  In step S704, the encryption key generation unit 104 generates an encryption key. At this time, the encryption key for encryption may be generated in any way. In addition, when generating the encryption key, the encryption layer 605 may be decrypted with the same key as the encryption key when encrypted, or may be decrypted with a different key for each area to be encrypted. . In step S705, the encryption processing unit 105 uses the encryption key to encrypt a new encryption layer (1102) and generate a second encryption layer 1104 (FIG. 10 (D3 ′)). . In step S706, the encoding process is executed for each layer image, and the layer images encoded in step S707 are combined into one (FIG. 10E) and stored in the data storage unit 107 as encoded data. .

  FIG. 6 is a diagram for specifically explaining the image processing. As a specific example, it is assumed that image processing is executed on the report 601 shown in FIG.

  Referring to FIG. 6A, the report 601 includes a table, and the contents of the table can be viewed only by some authorized persons with restrictions on browsing. It is assumed that image processing that can be seen by an unauthorized person is performed. Specifically, there is a case where an unauthorized secretary or the like wants to be able to see information such as the title, date, destination address, creator, etc. in order to manage the document.

  When the image of the report 601 is read in step S701, in the layer image generation unit 102 in step S703, the report 601 is changed to layer 1 (602) shown in FIG. 6 (B1) and FIG. 6 (B2). ) And a layer 2 (603) shown in FIG. 6 (B3).

  The image of layer 1 is an image that includes information that can be viewed without authorization, and the image of layer 2 is an image obtained by extracting information that is desired to be concealed by restricting browsing. Further, the layer 2 including the confidential information is a back layer, and the mask layer 604 specifies which layer is displayed in which region. That is, when decoded, the image of the layer 2 (603) which is the back layer is selected as the black portion (mask portion) in the mask layer 604, and the layer which is the fore layer is the white portion (non-mask portion). 1 (602) is selected.

  Therefore, the portion overlapping the white portion (non-mask portion) of the mask layer 604 in the layer 2 (603) as the back layer is not displayed even if it is decoded. Does not occur. For example, as shown in FIG. 6 (B3), the confidential information 607 may be newly filled therein. In the example shown in FIG. 6 (B3), the document creation date and the ID number are imaged and embedded as the confidential information 607. Of course, any other image may be embedded, or nothing may be embedded.

  In step S704, the encryption key generation unit 104 generates an encryption key. The encryption key for encryption is arbitrary data having a data size determined by encryption processing, and may be generated in any way. The creator needs to save this encryption key so that others cannot know it. In step S705, the encryption processing unit 105 uses the encryption key to encrypt the layer 2 (603) and generate the encryption layer 605 (FIG. 6 (B3 ')).

  Next, an image processing apparatus that decodes the decoded data processed in the above-described image processing apparatus 100 will be described.

  The image processing device that decrypts the encrypted image may have the same device configuration as the image processing device for encryption. In the present embodiment, the image processing device 400 that decrypts the image processed by the image processing device 100. The apparatus configuration is the same as the configuration shown in FIG. Of course, the encrypted image processing apparatus 100 may be used. In general, a general-purpose device such as a personal computer and its peripheral devices may be used.

  FIG. 7 is a block diagram illustrating a specific example of a functional configuration of an image processing apparatus 400 that can decode encoded data including an encrypted layer image.

  Referring to FIG. 7, an image processing apparatus 400 includes an image reading unit 401 that reads encoded data including an image encrypted by the image processing apparatus 100 as an input image, and a plurality of layers composed of input images. A layer image reading unit 402 that extracts an image, an image decoding unit 406 that decodes a layer image that is encoded data, an encrypted layer image acquisition unit 403 that extracts an encrypted layer image from the layer image, and an encrypted image An encryption key acquisition unit 404 that acquires an encryption key for decrypting the layer image, an encryption layer decryption unit 405 that decrypts the encrypted layer image, and an output data generation unit 407 that generates output data from the decrypted data It is comprised including.

  The image reading unit 401 is connected to a main memory, a communication device, and the like, reads encoded data image-processed by the image processing apparatus 100 as an input image, and inputs the read image to the layer image reading unit 402. The layer image reading unit 402 analyzes the encoded data, extracts a plurality of layer images constituting the encoded data, and inputs them to the image decoding unit 406.

  The image decoding unit 406 analyzes each layer image input from the layer image reading unit 402, decodes the layer image by a method according to the encoding method of each layer image, and encrypts the decrypted layer image. To enter.

  The encryption layer acquisition unit 403 analyzes the plurality of layer images decoded from the image input from the image decryption unit 406, extracts the encrypted layer images, and inputs them to the encryption layer decryption unit 405. In addition, an unencrypted layer image is input to the output data generation unit 407.

  As an example, the encryption key acquisition unit 404 is connected to a means for inputting user instructions such as a keyboard and a mouse, a communication device, etc., and acquires identification information of a user who wants to view an encrypted part, An encryption key is obtained using the information. Specifically, the encryption key is acquired by a method using the acquired identification information itself as an encryption key, or a method of converting the identification information acquired by a predetermined conversion process into an encryption key. The key acquisition method in the encryption key acquisition unit 404 is not limited in the present invention, and may be another method employed in a general encryption key method.

  The encryption layer decryption unit 405 acquires a key from the encryption key acquisition unit 404, decrypts the encrypted layer image input from the encryption layer acquisition unit 403, and inputs the decrypted layer image to the output data generation unit 407.

  The output data generation unit 407 generates output data by combining the layer image input from the encryption layer acquisition unit 403 and the layer image obtained by decrypting the encryption input from the encryption layer decryption unit 405, and generates output data. Output to.

  FIG. 8 is a flowchart showing the flow of image processing in the image processing apparatus 400 for decoding and displaying or printing encoded data including an encrypted layer image. The processing shown in the flowchart of FIG. 8 is implemented by executing a program acquired from the main memory or the like by the CPU of the image processing apparatus 400 and controlling each unit of FIG.

  Referring to FIG. 8, first, encoded data created in image processing apparatus 100 is read by image reading unit 401 (S901). When the encoded data read in step S901 is composed of a plurality of encoded layer images, the data is processed one by one. That is, the image decoding unit 406 confirms the presence or absence of an unprocessed layer image (S902). If there is an encoded layer image that has not been processed (YES in S902), the layer image is decoded. (S903).

  Further, the encrypted layer image acquisition unit 403 confirms whether the decrypted layer image is an encrypted layer image (S904), is an encrypted layer image (YES in S904), and the encryption key If the obtaining unit 404 can obtain the encryption key for decrypting the encrypted layer image (YES in S905), the encrypted layer image obtaining unit 403 decrypts the encrypted layer image (S906). If the encryption key has not been acquired (NO in S905), step S906 is skipped and the process proceeds to the next layer.

  When it is confirmed in step S902 that the processing for all the layer images has been completed (NO in S902), the output data generation unit 407 performs a plurality of (decoding) obtained by repeating steps S902 to S906. The layer images are combined (S907), and output such as screen display or printer printing is executed (S908).

  The above-described image processing apparatus 400 includes the encryption layer decryption unit 405 and can decrypt the encoded data including the encryption layer image. However, the image processing apparatus 400 includes the encryption layer decryption unit. 405 may not be included. FIG. 9 is a flowchart showing the flow of image processing when the image processing apparatus 400 does not include the encryption layer decryption unit 405 and does not decrypt the encryption layer image. The process shown in FIG. 9 is a process that does not include steps S904 to S906, which is a process of decrypting the encrypted layer image, among the processes shown in FIG. 8, and the other processes are the processes shown in FIG. It is the same.

  The encrypted image does not end the image display process itself even if the decryption process is not executed, and can be displayed as it is even if it remains encrypted. When the image processing apparatus 400 performs the image processing shown in FIG. 9 and decodes the image whose specific example is shown in FIG. 6 encoded by the image processing apparatus 100, as shown in FIG. In addition, the encrypted layer 605, which is an encrypted image layer, is displayed in the corresponding area without knowing the contents as it is. Even when the processing shown in FIG. 8 is executed, decryption is similarly performed when the encryption key for decrypting the encryption layer image is not acquired in the encryption key acquisition unit 404 in step S905. The encryption layer 605 that could not be converted is displayed in the corresponding area without knowing its contents.

  Furthermore, the above-described image processing method executed by the image processing apparatus 100 and the image processing method executed by the image processing apparatus 400 can be provided as programs. Such a program is stored in a computer-readable recording medium such as a flexible disk attached to the computer, a CD-ROM (Compact Disk-Read Only Memory), a ROM (Read Only Memory), a RAM (Random Access Memory), and a memory card. And can be provided as a program product. Alternatively, the program can be provided by being recorded on a recording medium such as a hard disk built in the computer. A program can also be provided by downloading via a network.

  The provided program product is installed in a program storage unit such as a hard disk and executed. The program product includes the program itself and a recording medium on which the program is recorded.

  The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

2 is a block diagram illustrating a specific example of a device configuration of an image processing apparatus 100. FIG. 3 is a block diagram illustrating a specific example of a functional configuration for performing image processing according to an embodiment in the image processing apparatus 100. FIG. As an example of MRC, it is a figure explaining MRC which employ | adopted the 1st method. It is a figure explaining MRC which has adopted the 2nd method as other examples of MRC. 3 is a flowchart showing a flow of image processing in the image processing apparatus 100. FIG. 3 is a diagram for specifically explaining image processing in the image processing apparatus 100. It is a block diagram which shows the specific example of a function structure of the image processing apparatus 400 which can decode the encoding data containing an encryption layer image. 5 is a flowchart illustrating a flow of image processing for decoding and displaying or printing encoded data including an encrypted layer image in the image processing apparatus 400. It is a flowchart which shows the flow of an image process when the image processing apparatus 400 does not decode an encryption layer image. It is a figure which illustrates concretely the image processing in the case of adding the area | region to encrypt.

Explanation of symbols

  100, 400 Image processing apparatus, 101 Image reading unit, 102 Layer image generation unit, 103 Layer selection unit, 104 Encryption key generation unit, 105 Encryption processing unit, 106 Image encoding unit, 107 Data storage unit, 201, 602 Forelayer 202, 603 Back layer, 203, 604 Mask layer, 204 image, 301 Transparent color area, 401 Image reading unit, 402 Layer image reading unit, 403 Encryption layer image acquisition unit, 404 Encryption key acquisition unit, 405 Encryption layer Decoding unit, 406 Image decoding unit, 407 Output data generation unit, 500 CPU, 501 display, 502 keyboard, 503 scanner, 504 printer, 505 main storage, 506 external storage, 507 mouse, 508 speaker, 509 communication device, 510 bus, 511 Storage medium, 601 report, 605 encryption layer.

Claims (15)

Image reading means for reading an input image;
A layer image generation means for generating a plurality of layer images respectively obtained by separating an image obtained by extracting an area to be encrypted and an image of another area not to be encrypted from the input image;
A layer selection means for selecting a layer image obtained by separating a region to be encrypted from the input image as a layer image to be encrypted from among the plurality of layer images;
Encryption key generating means for generating an encryption key for encrypting the selected layer image;
An encryption processing means for encrypting the layer image selected by the layer selection means using the encryption key;
A plurality of the layer images generated by the layer image generation means, wherein the layer image encrypted by the encryption processing means and the layer image not encrypted by the encryption processing means are encoded respectively. Image encoding means for
An image processing apparatus comprising: a data storage unit that stores encoded data including the plurality of layer images encoded by the image encoding unit. The layer image generation means includes a first layer image obtained by extracting an area in which text is written in the input image, and a second layer image obtained by extracting an image other than the text in the input image. The image processing apparatus according to claim 1, wherein the plurality of layer images are generated. The layer image generation means includes
A first layer image obtained by extracting a first region including text in the input image;
A second layer image obtained by extracting a second region other than the first region of the input image;
A third layer image indicating which of the first layer image and the second layer image is to be displayed at each point when the encoding is decoded;
The image processing apparatus according to claim 1, wherein the layer selection unit selects one of the first layer image and the second layer image. The layer image generation means includes
A first layer image obtained by extracting a first region to be encrypted from the input image;
A second layer image obtained by extracting a second region other than the first region of the input image;
A third layer image indicating which of the first layer image and the second layer image to display at each point when the encoding is decoded;
The image processing apparatus according to claim 1, wherein the layer selection unit selects the first layer image. The layer image generation means generates a plurality of layer images from the input image for each encryption key,
Said cryptographic processing means, for each encryption key, encrypting the selected layer picture of said layer image generation means and said plurality of layer images generated by in accordance with the encryption key, according to claim 1 to 4 An image processing apparatus according to any one of the above. The image processing apparatus according to claim 1, wherein the image encoding unit encodes each generated layer image. The image reading means reads the encoded data as the input image,
The image processing apparatus according to claim 1, wherein the layer image generation unit generates a plurality of layer images from the layer image included in the input image that is the encoded data.   The image processing apparatus according to claim 1, wherein the encryption processing unit encrypts the layer image using a common key encryption method or a public key encryption method.   The image processing apparatus according to claim 1, wherein the encryption key generation unit generates the encryption key based on a unique identifier of a user who has an authority to decrypt the encrypted layer image. . Image reading means for reading the encoded data generated by the image processing device according to claim 1 as an input image;
Layer image reading means for taking out an encoded layer image from the input image;
Image decoding means for decoding the encoded layer image;
An encrypted layer image acquisition means for extracting an encrypted layer image from the decrypted layer images;
Encryption key acquisition means for acquiring an encryption key for decrypting the encrypted layer image;
Encrypted layer decrypting means for decrypting the encrypted layer image using the encryption key;
An output for generating output data from the layer image decrypted by the image decryption means, the layer image decrypted by the encryption layer decryption means, and the layer image not encrypted An image processing apparatus comprising data generation means. A step of reading an input image in an image reading means of the image processing apparatus;
Generating a plurality of layer images respectively obtained by separating an image obtained by extracting an area to be encrypted and an image of another area not to be encrypted from the input image;
Selecting a layer image obtained by separating a region to be encrypted from the input image as a layer image to be encrypted from among the plurality of layer images;
Encrypting the selected layer image;
A plurality of generated layer images, each of which encodes the encrypted layer image and the unencrypted layer image;
An image processing method comprising: outputting encoded data including the plurality of encoded layer images from the image processing device. A step of reading encoded data generated by the image processing method according to claim 11 as an input image in an image reading means of the image processing device;
Extracting an encoded layer image from the input image;
Decoding the encoded layer image;
Extracting an encrypted layer image from the decrypted layer images;
Decrypting the encrypted layer image;
An image processing method comprising: generating the output data from the layer image obtained by decoding the encoding and the layer image obtained by decoding the encryption, and the layer image not encrypted. A program for causing a computer to execute image processing in an image processing apparatus,
Reading an input image in the image reading means of the image processing apparatus;
Generating a plurality of layer images respectively obtained by separating an image obtained by extracting an area to be encrypted and an image of another area not to be encrypted from the input image;
Selecting a layer image obtained by separating a region to be encrypted from the input image as a layer image to be encrypted from among the plurality of layer images;
Encrypting the selected layer image;
A plurality of the generated layer images, wherein the encrypted layer image and the unencrypted layer image are respectively encoded;
An image processing program causing the image processing device to execute encoded data including a plurality of encoded layer images. A program for causing a computer to execute image processing in an image processing apparatus,
Reading the encoded data generated by the computer by the image processing program according to claim 13 as an input image in the image reading means of the image processing apparatus;
Extracting an encoded layer image from the input image;
Decoding the encoded layer image;
Extracting an encrypted layer image from the decrypted layer images;
Decrypting the encrypted layer image;
An image processing program for executing the step of generating output data from the layer image obtained by decoding the encryption and the layer image obtained by decoding the encryption. .   A computer-readable recording medium for recording the image processing program according to claim 13 or 14.

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